A bitterly divided US Senate yesterday began seeking a compromise to defuse the row over President Bill Clinton's proposal to lift the ban on homosexuals in the armed forces. Failure would at least sour his relations with Congress and might imperil his infinitely more important plan to cut the deficit and re-order the national economy.

As the Senate Armed Services Committee hearings on whether to lift the half-century-old ban opened before a packed audience on Capitol Hill, the battle lines were more sharply drawn than ever, with polls suggesting that public opinion too is split down the middle on the issue.

Ranged against the idea, at least in the original form put forward by the President, are virtually the entire US military establishment and - almost certainly - a majority of the Senate, headed by the Committee's influential chairman, Senator Sam Nunn of Georgia.

No less intense, however, is support from liberal groups led by the powerful gay-rights lobby, which plans demonstrations and protests over the 12 weeks the hearings are scheduled to last, spearheaded by a march on Washington in mid-April.

Right now, the prospects of bridging the gap look thin. President Clinton's first attempt to do so last week, when he suggested homosexuals might be confined to certain duties, only succeeded in enraging gay groups, who argue that this would amount to creation of 'second-class soldiers' - a discrimination they say would violate the constitution. And how, others ask, could homosexuals be identified if they were not obliged to disclose their sexual leanings when they joined the armed services?

At yesterday's opening session, Mr Nunn hinted at what has been called a 'don't ask, don't tell, don't flaunt' formula - in other words, little different from the temporary ruling now in force, until Defence Secretary Les Aspin comes up with a definitive policy by mid-July. That falls far short of the demands of homosexual-rights activists, who see this high-profile controversy as an opportunity to further their campaign for full recognition in every walk of life.

Their opponents present a vision of a military held hostage by gay groups emboldened by a lifting of the ban to insist on equal benefits for unmarried homosexual partners. Worse still, they argue, the combat effectiveness and 'unit cohesion' of the US armed forces would be dangerously undermined.

For Mr Clinton, there is the separate, potentially massive political risk of alienating fellow Democrats such as Senator Nunn at the very moment he needs party unity to push through his economic package. As Senate Republican leader Bob Dole put it at the weekend, the President is in 'very deep water'.

Mr Clinton's response is to walk the tightrope between the 'status' and 'behaviour' of homosexual servicemen. But, warns Mr Nunn, 'when you declare your status, you are describing your behaviour'.